Garden owners with flat bird feeders or bird tables are being urged to switch to alternative types of feeders for a crucial reason. According to the Royal Society for the Protection of Birds (RSPB), three species of common garden birds face the threat of a disease that can be readily spread through flat feeders.
On its website, the RSPB’s latest guidance highlights that trichomonosis is triggering a considerable decline in the populations of greenfinch, chaffinch and bullfinch. Trichomonosis is a condition caused by the parasite Trichomonas gallinae, which attacks the throat and gullet, making it increasingly difficult for birds to swallow food.
The RSPB says: “Across the UK, trichomonosis has caused serious declines in Greenfinch and Chaffinch populations and may now be causing a rapid decline amongst Bullfinches. The scientific evidence shows that the risk of trichomonosis outbreaks is highest in summer and autumn.”
RSPB research has established that bird tables and other flat feeders carry the greatest risk of transmitting the disease. Birds suffering from trichomonosis tend to perch on flat surfaces when attempting to feed. The illness renders swallowing extremely difficult, causing affected birds to regurgitate contaminated food back onto the flat surface, where it then becomes accessible to healthy birds, reports the Liverpool Echo.
The RSPB states that even with daily cleaning of feeders, healthy birds can still consume food that was regurgitated previously. That’s why the charity advises against using any flat-surface feeders, such as bird tables and window feeders, to provide food for birds.
It stated: “Don’t use bird feeders with flat surfaces, such as bird tables, window feeders and feeders with trays. Research has confirmed that there’s a higher risk of disease spreading on flat surfaces, where contaminated food can collect.”
Describing how trichomonosis is passed between birds, the RSPB states: “The research shows that transmission is most likely through birds sharing contaminated food. In a recent study of shared feeding sites in gardens, no trichomonosis was found on feeder surfaces (0 out of 79 feeders tested). This suggests that the equipment itself isn’t the main risk.
“However, trichomonosis was detected on food in feeders, base trays, and on the ground below. Sick birds often regurgitate food that they cannot swallow, and this food is likely to be contaminated with the parasite.”
The charity is appealing to people to temporarily halt feeding garden birds particular foods between May 1 and October 31. A statement on its website reads: “Our Conservation Scientists have worked with other expert partners to find a solution.
“We now recommend that you pause feeding garden birds seeds and peanuts between 1 May and 31 October. You can continue to offer small amounts of mealworms, fatballs or suet. During spring and summer, dried mealworms can be soaked in water to make them easier for nestlings to eat.”
The charity states that finch species tend to favour seeds, yet when seeds are unavailable, they will turn to peanuts instead. As finches seldom consume fatballs, suet, and mealworms, the RSPB advises these foods carry a low risk of spreading trichomonosis.
It adds: “To further reduce the risk of disease, we also recommend that you: feed only small amounts; don’t use bird feeders with flat surfaces; keep your feeders clean; and only put out water if you can change it every day.”
The RSPB also recommends that people help birds find their own food. It says: “One of the best ways to support garden birds in the long-term is to help them find their own food. So fill your outdoor space with bird-friendly plants – such as sunflowers, teasels and ivy. These help provide natural food sources for birds.”
Is it safer to simply stop feeding birds altogether?
The RSPB said: “The evidence review found that it’s often beneficial to feed birds during winter, especially during cold weather when natural food can be in short supply. Birds can also benefit from feeding between March and April. This is sometimes called the ‘hungry gap’ as there are often fewer natural foods available for seed-eating birds such as finches at this time of year.
“Furthermore, although trichomonosis occurs all year round, the parasite is killed by cold weather, and the likelihood of disease outbreaks is lower during winter. We have carefully balanced the benefits of feeding against the risks of disease, and we believe that we can continue to feed our garden birds, as long as we feed the right types of food at the right time of year. By following our guidance to feed seasonally and feed safely, we can all help protect the future of our birds.”